DE1947090A1 - Device for determining the imbalance of wheels - Google Patents

Description

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BATH

a speed at which the natural frequency of the Ätisvraclit system is exceeded, called low-tuned devices. , at which one remains below the ElgenfrecpieBZ: the system, highly coordinated facilities. -

Bie known Äusviraels.teinrlGliitBngen fiir Fanrzengräder include zwt first or second Gkrappe "bie appropriate operating catfish was gewanit because the migration of the seiiwlnigenden at a low abgestlitimten system; Workpiece In the order of magnitude of the distance between the Hassenaelise iron and the workpiece's focal length. In the case of a ¹ device "by Resooüanztjp, the amount of sideways movement of the workpiece is limited to the system used in each case _r tind can be measured with relatively inexpensive EInrlebitBnigen evaluated as the on seiiwingenden Werkstiiek;! abgenonmrene signal is relatively free StorgeräussebieB, on the other hand iiaben solelie EinrieMtEfig the following laekteile.

t., Ba is the amount or the Arapältiide the Seliw; IügiJH! g a function of the distance Her Hassenaeisse wan the B ^ eiiacnse of the workshop kess * splegei-fe i.ie durek the AnizelgevorrlitTJiig display this Be ^ Ielrimg again, so äaB iie exact.

eatlmmBng the compensation: - or Ansswracilitgewlc3i.fe tot p: agllc | i. Isrfe if let Ässe ^ feonilgprai-feiop des Werkstülcfees got | pn5 ^ |. _: .,

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like ¥ © rkstüffike naelteiriaiidieE 'aäTESgewneiitet who fsp # _w Mp (ieiaitet; | eäoi © Iii the ro; Tffit; iiiein: äßlgjeiii Apawp; Cmen: ¥ © one; e^Efe@M.ieEneni Haciifep ,, ia mtoh the.. . Rädsr ^{1 of} the pp

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Lent mass configurations occur.

2. It is difficult and uneconomical to have a low discounted, agreed to train Ausvruchteinrichtung so that the for the balance weights required for both correction levels can be determined in a single operation can. The normal procedure is to first determine the weights required for a correction plane and the correction is completed before balancing in the second plane is started. This procedure is necessarily time consuming.

3. In order to obtain a low resonance point, the Peder constant of the suspension must be small. That on this The flexible system obtained in this way can easily be affected by external disturbances, e.g. by the use of a drive device for the workpiece. It is therefore generally necessary to turn off the drive before reading off a measured value to separate from the workpiece. This, in addition to slowing down the testing process, makes it a significant mechanical one Effort required, which makes the construction of the device more expensive.

4. Resonance-type devices have similar disadvantages like the low-polled facilities. In addition, there is the disadvantage that the workpiece is brought up to one speed must, *> e * i which the resonance point is exceeded, and that one then has to let the workpiece gradually slow down so that the resonance speed is passed through. This The process is extremely time consuming.

The highly coordinated procedure has the clear advantage that only the forces existing in the system are measured, since the migration of the system is small. With others

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Words are those exerted on the supports of the workpiece Reaction forces proportional to the amount of unbalance present in the workpiece and fairly independent of the mass of the workpiece itself. With car wheels, of which one knows neither the mass nor the mass configuration, is this is of great advantage. However, the usual highly coordinated systems also have disadvantages. First, you need to a machine for balancing in two planes, four parameters are first set by the operator ^ before the actual balancing can be started. Second, the signals provided by the machine are small and in usually superimposed by a strong background noise.

The object of the invention is to provide a simple one built, easy-to-use device for determining the imbalance of wheels, as a highly tuned device works and avoids the disadvantages mentioned above or at least reduces them to a minimum.

This object is achieved in a device of the type mentioned, ^a Orfindungsgemäß supports the shaft at a distance at two bearing locations and is provided with a fixing device by means of which a wheel with its inner balancing plane the adjacent bearing perpendicular to W _e lle-enforcing fastened is that the The shaft can be driven at a fixed speed, which is lower than the speed corresponding to the natural frequency of the shaft and its storage in the sense of a high tuning of the device, and that the measuring sensors are connected to an electrical computing circuit, which the values of at least two during one operation , indicates the balancing weights to be attached to the examined wheel in the inner and outer balancing plane in the form of signals. At a normal

009813/02 5 8

BATH original

paint car wheel correspond to the inner and outer balance plane the two rim edges to which the balancing weights are attached.

The device according to the invention is designed in the mechanical part so that an extremely simple electrical Analogy results. Therefore, in order to perform an accurate balance, the operator only needs two easily identifiable ones Take into account parameters, namely the diameter of the wheel given by the mentioned edges and its Broad. .

Each measuring transducer is preferably designed as a measuring transducer which generates a signal which, according to amplitude and the phase position corresponds to the magnitude or direction of the dynamic reaction forces occurring at the measuring point. In order to A particularly low noise level can be achieved.

A particularly simple arithmetic circuit comprises a series circuit of a voltage divider that can be adjusted according to the ratio of the distance between the bearing points to the distance between the balancing planes and a fixed resistor which is connected to the first measuring sensor located further away from the free end of the shaft, " as well as a matching stage, one input of which is connected to the tap of the voltage divider and the other input to the second t-sensor, gogebenonfalla via a fixed voltage divider, connected to the output Jer Surauierabure a signal that corresponds to a balance weight .. -ia> 3 im Fail in darinnen, dir; tiotuu'libarl.o La ^ orateHe tiureLijw t, iandeu AibJv / iHmtob.! ^ ^! In « ^r > brus ·; - ¹ «ir: t ,, Wonu c'uil3-ii;d:" iii] ^ w ei f.luLchzex big bnlJlbifUiaro. W: h · -. M- ^ L ¹ VH '■ /) :> üum rt i' ■ · ', ^ - »"<·· ■ - -, .- .. l' üL ·) VofMddling .. · «, · ii" f iivjMi U lii:; /. ■ · i u.-ii H-ii -. ^ wi / ijOituiui. ' do the hummingbirds separate,

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when the other bridges the Pestwiderstand, the feature is realized in einfachster manner, the same arithmetic circuit dßß also used to determine the Auswuehtgewichtes, to be mounted passing through balancing plane in the outer shaft outside the portion between the two bearing points on the wheel.

By means of a graduation that runs around the shaft Stroboscopic lamp, which can be triggered by a trigger switch connected to the output of the arithmetic unit the points ara the circumference of the wheel, where counterweights are to be attached, can be visibly displayed.

So that a wheel to be examined can easily be aligned so that its inner balancing plane ^ exactly the neighboring one through the bearing point of the shaft, the fastening device for the wheel to be examined is best in the longitudinal direction the shaft can be moved.

The invention is with further advantageous details in the following with reference to schematic drawings on a Embodiment and several modifications thereof explained. It »own:

Fig. I in an ohematic representation that looks at the side a mechanical device supporting the wheel under investigation an invention facility,

flg. 2 on for len operation of the in Pig. I -gea "? ..g th Device valid force diagramni,.

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8AD ORIGINAL

FIG. 4 shows the diagram shown in FIG. 3 with a different position of the switch for determining the in Pig. 2 shown value Y,

5 shows the circuit diagram of a modified embodiment a part of the arithmetic circuit for determining the values I and Y shown in FIG. 2 in the form of voltage changes instead of in the form of current changes,

6 shows the circuit diagram of an embodiment of a part of the computing circuit as an example of one for balancing embodiment practically used by wheels,

7 shows an isometric view of a device according to the invention in a simplified representation,

Fig. 8 is a partially sectioned side view of the device shown in Fig. 7, with some Parts are omitted for the sake of clarity,

Fig. 9 is a cross section on an enlarged scale a telescopic shaft and its suspension, at the free end of which a wheel to be examined can be attached ' is,

10 shows the block diagram of an embodiment of the entire electrical system of a device according to the invention.

It is known that the unbalance of a car wheel, for example, can be resolved in any two planes, which one Balancing planes are called and by the opposite Edges of the wheel rim are defined. The two balancing planes are in the following inner and outer balancing

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called balancing plane. It is also known that an eccentric Mass, such as the unbalance of a rotating shaft, exerts a force whose amount corresponds to the amount of the mass and the distance of the mass from the center axis of the shaft is proportional. Such a circulating force creates moments which are radially in two reaction zones, in one Forces lying on the plane can be dissolved. E.g. the two reaction zones have one in the longitudinal direction of the shaft Distance from one another and one of them is essentially in the same plane extending transversely to the shaft arranged in which the inner balancing plane of the examined wheel is also arranged. A corresponding arrangement is shown in Figs. In such a rigid system, the simple force diagram shown in FIG. 2 represents is an exact analogy of the system at a given point in time.

Such a geometric arrangement can be used to generate an electrical analogy to a common Display system for both balancing planes X and Y to supply information so that · the amount and the position the existing imbalance can be precisely determined in each balancing plane.

The one used in the device according to the invention actual mechanical device is shown in FIG. A wheel 2 is detachably attached to a rotatable shaft 3, which is supported in two reaction zones P1 and P2. The two balancing planes are marked with the letters X and Y. and it can be seen that the inner balance plane X substantially coincides with the reaction zone P1.

The following can be derived from the force diagram of FIG. 2 Derive expressions 1 and 2:

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BATH ORIGINAL

Expression 1

Y = -Ρ2. | X = PI-Y (1 + I),

Substituting Y results in

Expression 2

X = P1 + P2.g (1 + I) = P1 + P2 (° - + 1)

and with ^ = E:
a

Y = -K.P2 X = P1 + -P2 (K + 1)

The due to the imbalance of the examined wheel. forces acting in the balancing planes Y and X are therefore expressed by F1 and P2 in reaction zones P1 and P2, respectively. The expressions for the forces Y and X included as a factor for P2 the quantity K or K + T.

Pig. 3 shows an analog electrical circuit arrangement to generate an electrical signal proportional to the force X from two signal currents 11 and 12, which are proportional to the reaction forces P1 and P2 in the reaction zones P1 and P2, respectively. These signals are used to generate a voltage across a resistor. The tensions are in a e.g. in Pig. shown summing step added.

To generate a signal proportional to the force X, two signals are mixed in the following manner. First the current I1 is used to "generate a voltage across a resistor R1, which voltage reaches the summing stage." Second, the signal 12 is fed to a network which is a potentiometer or other variable resistor

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VR1 and a fixed resistor R2. The potentiometer VR1 represents the size k in the expression J? 2 · (k + 1) · The size of the resistor R2 is chosen so that it represents the value 1 in the above expression.

Fig. 4 shows how after actuation of the two in Pig. 3 Switches SW1 and SW2 shown can generate a signal which is proportional to the force Y. The size k becomes the same as described above., but the resistor R2 is short-circuited and the signal 11 is disconnected from the circuit. Accordingly, the circuit represents an electrical analogy to the expression Y = -k; P2, but with the minus sign is omitted. The analogy is thus phase-shifted by 180 °, so that the associated display system is set in this way should be, "invert the corresponding signal" to give a correct indication. The correction however, only affects the display of the unbalance point and not its amplitude.

It has already been mentioned that the signals used in the exemplary embodiment described above are caused by current intensities are shown in the circuit. An easier one to use electrical analogue is obtained in the form of the modified, in Pig. 5 circuit shown, in which the reaction forces in zones P1 and P2 by proportional Stresses are represented. The embodiment includes a further switch SW3, which is assigned to a resistor R3, whose V / ert that of the resistor R2 to keep the resistance of the circuit constant. The switches shown are preferably all connected to one another mechanically coupled.

The signal path responsible for the reaction force P1 is responsible for it the circuit lying resistor RI is through a Replaced voltage divider with resistors R4 and R5. the

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BATH ORIGINAL

19A7090

mutual relationship of the various "- ate resistors of this circuit depends on the · jewei: ¹ 1 r geotnetrischen parameters of the mechanical part of the ,," λγ e.ite finishing off because in _t the practice of Wertebereiolij where k is the size be?. can, is limited, the potentiometer VR1 is preferably replaced by a series connection of a potentiometer and a fixed resistor at the lower end.

The following apply to the practical example shown in FIG following values:

Wheel diameter: .25 to 40 cm
a: 10 to 20 cm
b: 20 cm

Pig. 6 also shows a circuit part which has a variable resistor VR2 and in series therewith a includes fixed resistance. The circuit part is used to take into account the different, by the respective Dimensions of the wheel rims specified diameter on which the balance weights are attached. The changeable ones Resistors or potentiometers VR1 and VR2 are preferably corresponding to the width or the diameter of the wheel rim calibrated.

The mechanical part of a preferred embodiment of the invention is in the pig. 7 * 8 and 9 shown. A rotatable Shaft 3 extends through a cylindrical housing 4 which is part of a support for the shaft. End sections 6 of the housing 4 are partially separated from a central main section 11 by a plurality of arcuate slots 8 separated, so that a flexible or gimbal-like connection

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• ■■■ ·. ■ - 12 - · '·· "■ ·· ■■ ..

• between each of the two end sections and the middle one Main portion of the housing is formed. Within the central main section '11 are two in the longitudinal direction thereof spaced apart ball bearings 9

(i and 9a arranged so that cross movements relative to the end sections the housing and a stationary support structure, which arise as a result of vibrations, which occur when the shaft rotates in the housing.

The end sections 6 are supported by means of a plurality of arms 10, which preferably on opposite sides of each End portion 6 of the housing and on opposite ends of the Slütz structure 7 are attached.

The shaft and an attached wheel must have a can be rotated at a specified speed. Various drives can be used for this. In the exemplary embodiment includes the drive is an electric motor 13 which is fastened to the support structure 7 and via a drive belt 14 drives a pulley 15 on shaft 3. The pulley is seated on that of the fastening device for the wheel far end of the shaft.

The fastening device for the wheel comprises a disc-shaped flange 16 which is connected to the shaft and is at a suitable distance from the adjacent bearing 9a. If a wheel 2 on the shaft next to the flange is attached, the flange is received in the central, plate-shaped vaulted section 17, which each Autoffiormalerweis'e having on the inside. This ensures that the inner balancing plane of the wheel supports the adjacent reaction zone in which the shaft at the adjacent bearing point is brought into alignment.

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^009813/0258

. . ·; 19A7Q9Q

The actual device for attaching a wheel to be examined to the shaft 3 can be in various ways Way to be formed and includes the Ausfüterungsbeispiel a stepped collar 20 which can be placed against the flange 16 and a removable collar 20 which is longitudinally displaceable on the shaft Cone 21. To attach a wheel, the collar and the cone are placed on opposite sides of the wheel and compressed so that the wheel is wedged between the two parts. The inward movement of the cone on the Shaft can be effected by means of a manually rotatable screw 22 which is inserted into an axial threaded hole at the end the shaft 3 is screwed in. The cone can have a parallel or tapered section at the tip or forehead · be provided to facilitate the assembly of the wheel and the cone on the shaft.

A suitable! Foot or Hand switch provided.

. - So that the inner balancing plane of the wheel is exactly in the Level of the adjacent reaction zone or, precisely, the adjacent bearing point can be arranged so as to permeate the fastening device for the wheel to be examined is displaceable in the longitudinal direction of the shaft. To do this is the wave designed as a sleeve in which a shaft 26, which carries the fastening device at one end, telescopically is arranged displaceably. The shaft has a clamping device by means of which it can be in any position can be determined within the sleeve.

The shaft 26 is on that of the fastening device for clamping opposite end provided with an axial bore 27 in which a wedge cone 28 is arranged, which is connected to a fixed end cap 36 of the sleeve.

009813/0258 " ^H.

The wedge cone 28 is formed by means of a spring-loaded cone 29 . expandable so that the shaft can be in any position can be locked relative to the sleeve. To release the clamping device there is a rod 31 which can be displaced in the longitudinal direction of the shaft provided, at one end of which the cone 29 is attached and the other end of which extends out of the shaft and the sleeve and is provided with a rounded head piece 32. The rod is surrounded by a helical spring 33 which clamped between a nut 34 or other stop on the shaft and between the fixed end cap 36 of the sleeve is. For example, an articulated lever 37 can act on the head piece, which is hinged to the support structure 7 and by means of a suitable linkage can be actuated via a foot pedal or a pivotable hand lever.

In addition, a not shown in the figure, on the Support structure 7 fastened stop may be provided, which is adjustable along a scale and serves to the inner balancing plane of a wheel to be examined by placing the wheel against the stop in exactly the right orientation relative to the shaft, in which the inner selection plane or the inner rim edge is exactly the adjacent one Custody interspersed.

The electrical circuits of the device according to the invention are designed as a separate electronic unit and in a housing 41 next to the end to be examined Wheel housed.

The link between the mechanical and electrical Ewei part of the facility according to the invention Measuring transducers in the form of transducers 42 and 43, where the two storage locations in the reaction zones where the

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009813/02 5 8

ORIGINAL BATHROOM

■ - 15 - ·

Shaft is supported, each associated with a transducer. The two measuring transducers are e.g. attached to the support arms 10 or formed with these as a unit, which with the opposite end portions 6 of the housing for the shaft are connected.

In the preferred embodiment, the electronic component comprises two impedance converters 51 , each assigned to a measuring transducer, cf. 10. The measuring transducer assigned to the bearing point immediately next to the fastening device for the wheel is referred to below as the inner measuring transducer 42, while the other is called the outer measuring transducer 43.

The two impedance converters 51 give their output signal to a working on the basis of analog ratio formation Computing circuit 52, which has a mixer stage in the form of a summing stage 53 and one or more amplifiers 54 are connected downstream. The 'amplifiers' in turn send their signal to two measuring instruments 56 and 57 ..

In addition, the output signals of the amplifiers pass through a squaring circuit 58, a phase counter 59 and a trigger circuit 61 with a trigger coil to a Strobe flashlight 62 which one attached to the shaft and is associated with this rotating table or scale 63.

The signals emitted by the transmitters 42, 43 signals are fed to two separate pre-amplifiers which operate as an impedance converter and reduce the impedance to a relatively low value change substantially ZVT without the amplitude of the signals. The impedance converters can

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009813/0258

z »B. integrated circuits with field effect transistors include.

The two signals formed in this way reach the aforementioned computing circuit 52, which is an electrical The analogy of the expressions forms which is taken from the circuits described above with reference to FIGS. 3 to 6. from The computing circuit outputs the signals to the mixer, in which the algebraic sum of the signals is formed will. The output of the summing stage can be given to a voltage divider, in which e.g. by means of a second potentiometer, the signal amplitude is varied to take account of the wheel diameter.

•: Γ

After the signals have passed an associated amplifier, which may include a low-pass filter, they arrive at a wide amplifier 54a, which is a Double iD filter can include that over a narrow one Frequency range is tunable. The voting regulation works as a phase-shifting network, so that the lightning bolt generated by the aforementioned tube 62 coincides with the unbalance point of the Rades can be made coicident.

The output of this stage of the electrical circuit has two functions .. It is e.g. via suitable switches Supplied to rectifiers, which in turn charge a capacitor, the clamping voltage of which by means of an electrometer circuit and one of the measuring instruments 56 or 57 can be determined. The measuring instruments are designed so that they show the mass needed to balance the wheel on it must be attached in the inner and outer balancing plane. The measuring circuits cause in a known manner that the pointer deflection remains the same as the rotation of the Shaft and the wheel has stopped.

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0 0 9 813/0258

BATH

• - 17 - '

The second puncture of the from the output of the amplifier The signal picked up is the triggering of the flash tube 62. For this purpose, the signal is first precisely squared in a suitable circuit and then j becomes dependent on which balancing plane is being observed, the appropriate phase is selected, which is fed to the Iriggersystem 61, the a pulse to ignite the strobe flash tube 62 is generated.

The markings on the rotating scale or graduation 63 are points of the 3? Elg @nrandes distributed around the circumference examined wheel assigned. Therefore, the forms made visible by the flash tube during the rotation of the wheel Markings of a display for the positions or places in the inner and outer AuBWUchtebene of the rim, at which Balance weights of a certain mass must be attached.

From the foregoing it can be seen that by means of the device according to the invention, in one operation can determine both the weight and the location of balancing weights that are used for balancing a car wheel or similar wheel are required.

Most automobile and similar wheels have a disc rim with an opening in the middle through which the shaft or the shaft during cter examination of the wheel can pass through. In the case of wheels that do not have a central opening, however, it does the telescopic one Formation of the shaft possible that the wheel is displaceable in the longitudinal direction of the shaft and are therefore correctly arranged can without the shaft having to reach through the wheel.

In addition, the telescopic design of the wire facilitates the alignment of the inner balancing plane of the wheel with that of the adjacent reaction zone when the wheel is attached to the rotatable shaft.

6965 adaptations

0 09813 / 02S8 ~ "" ~ "

Claims (11)

DH-INCf-WUBSTIIOB ¹ F. . . . . "8 ^ UNCHBN 0 (8 GDPL. ING. G. PULSE '. SCHWBiGEHSTHASSE 8 BR.K.T.PECHMANN nurox Γ.δΟββΙ DR.ING. D. BBHRBNS ig nuauKiiASBUsii 'PATENT ADVOCATE »*> »» OWOIPAIMI MÜVOHM 1A-36 858 P a _n te C ₁ t _ini aass £ i O ₁₁ he Li.) Device for determining the unbalance γοη baths, in particular car wheels _s P & $ eiuer ds @ libaEei3 ¥ efl.e, which supports several bearing racks on a free lade © ia © fastening device for a UDtersi ^ cheDäes Ra & .- has imä aa several bearings ₉ aa Deisen analog electrical signals donating MeßaufnehmeE for Reaktioaskräfte during rotation angetoaeht sii3ö _P characterized EKENN g. Iseichaet that the shaft (5) supports at a distance as sv / ei fegerstellen (9; 9a) and is provided with a bit of a fastening device (16), by means of which a wheel (2) with its inner alignment plane (X ) the adjacent bearing point perpendicular to the shaft is firmly fastened, that the shaft can be driven at a fixed speed which is more than that of the natural frequency of the shaft and its bearing corresponding speed in the sense of a high support of the device, and that the transducers (42, 43) to an electrical © Rtolienschaltung (52 _t '53) connected-are; weleli © the values roindesteiie, awei © i? _f indicates the balancing weights to be attached to the examined wheel in the inner and outer balancing plane (1 and Y) in the form of signals. 2. Device according to claim 1, characterized in that g e k e η η, that each transducer is designed as a transducer (42; -43) which generates a signal that according to amplitude and phase position of the. Corresponds to the size or direction of the dynamic reaction forces occurring at the measuring point. D09813 / 0258 ^ß AD ORIGINAL 3. Device according to claim 2, characterized in that the computing circuit (52, 53) has a _{Series connection of a voltage divider (VR 1} ) that can be adjusted according to the ratio of the distance between the bearing points (9; 9a) to the distance between the balancing planes (Xj Y) and a plague resistor (R-,) which is connected to the first, to the free At the end of the shaft (3) a measuring transducer (43) arranged further away is connected, as well as a summing stage (53), one input of which is connected to the tap of the voltage divider and the other input of which is connected to the second measuring transducer (42), possibly via a fixed voltage divider ( R *, R ₁ -), is connected. 4. Device according to claim 3, characterized in that two simultaneously actuatable switches (SW1; SW2) are provided, one of which separates the connection between the second measuring transducer (42) and the summing stage (53) when the other separates the fixed resistor (R ₂ ) bridged. 5. Device according to one of claims 1 to 4, characterized in that at the output of the computing circuit (52, 53) a trigger circuit (51) for a strobe lamp (62) is connected, which illuminates a division (63) running around the shaft (3). 6. Device according to one of claims 1 to 5, characterized in that the fastening device (16) is displaceable in the longitudinal direction of the shaft (3). 7. Device according to claim 6, characterized in that the fastening device (16) on the The end of a shaft (26) is seated, which is received in a longitudinally displaceable manner in a bore in the shaft (3) and is - 3 009813/0258 ble clamping device (28, 29) can be locked. 8. Device according to claim 7 »characterized by g e k e η η that the clamping device has a wedge ·: cone (28) within the shaft (26) and a wedge cone spreading, spring-loaded cone (29), which is displaceable against the action of each (33). 9. Device according to one of claims 1 to 8, characterized that the shaft (3) by means of two ball bearings (9; 9a) in the middle section (11) of a Housing (4) is mounted, the device-fixedly supported end sections (6) only in places with the middle section connected and can be moved flexibly with respect to this. 10. Device according to claim 9, characterized in that the two transducers (42; 43) to the End sections (6) of the housing (4) are attached. 11. Device according to one of claims 1 to 10, characterized in that one with the help of a scale adjustable, device-fixed stop is provided for the wheel to be examined (2). ⁶⁹⁶⁵ 009813/0258 , ^9λ ·· Blank page